In the world, there are many people for whom it is difficult to enjoy the convenience of electricity, such as residents of an area where neither a power generator set nor a power transmission line is installed and nomads who have no settled residence. In the past, those people used a generator that is easy to install, such as a compact solar photovoltaic panel, to generate electric power. However, the solar photovoltaic panel can generate electric power only during the daytime when the panel can receive sunlight and therefore has a problem that the panel cannot electric power during the night when electric power is most needed for illumination or other purposes.
In recent years, compact wind power generators have been proposed that have simple structures, are robust and easy to install and can generate electric power even during the night.
For example, in Japanese Patent No. 3451085, there is proposed a wind turbine for wind power generation having a plurality of blades arranged in a plane perpendicular to a vertical rotation shaft at regular angular intervals about the vertical rotation shaft, in which the blades have an airfoil shape, and the blade is partially cut away on the rotation shaft side from a point at a distance of 35% to 45% of the chord length from the front edge to the rear edge (Patent Literature 1). According to Patent Literature 1, the wind turbine for wind power generation can efficiently revolve even when the wind turbine is activated or even in a low wind speed range, because the cut-away part of the blade on the side of the airfoil lower surface generates a high air resistance, and characteristics of the drag type wind turbine and characteristics of the lift type wind turbine are effectively combined.